For me it was paradox games that ruined civ, they're so much more in depth, your decisions don't just have effects but the have ripple effects, an English Portu

For me it was paradox games that ruined civ, they're so much more in depth, your decisions don't just have effects but the have ripple effects, an English Portuguese alliance could take down the Spanish fleet and allow Ottoman hegemony over the Mediterranean for instance. A large part of that is the sheer number of nations, but also some good modelling of their motivations. They also feature some much better (but now largely gimped) late game features. An inheritance war can tear empires apart in CK2, culture and colonies may revolt in EU4, communists will start a revolution if they don't get social reforms in vicky and and soldiers will become more loyal to their general than you in rome.